\chapter{$C^*$-Algebras} \label{chap:c-star-algebras} \input{./involution.tex} \input{./sub.tex} \input{./unitary.tex} \input{./sa.tex} \input{./homomorphism.tex} \input{./gelfand.tex} \input{./cont.tex} \input{./order.tex} \input{./positive.tex} \input{./state.tex} \input{./gns.tex} \input{./non-unital.tex} \input{./quotients.tex}